2011/05/31 by D. V. Bugg · 1 citation
Physics and Astronomy · #Field (mathematics) #Nuclear physics research studies #Particle physics theoretical and experimental studies #Phase (matter) #Phase space #Product (mathematics) #Quantum Chromodynamics and Particle Interactions #Space (punctuation) #hep-ex #hep-ph
paper · pdf · doi:10.1209/0295-5075/96/11002
published as Europhys. Lett.96:11002, 2011 · 5 pages, 5 figures. Major revision correcting a mistake in the earlier version, and including full calculations of cusp effects; two references added and corrections to Figs. 2(a) and 3(a)
arxiv created 2011/07/20 · openalex publication_date 2011/09/15 · arxiv updated 2011/09/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Belle report data on ϒ(5 S )→ϒ(1 S , 2 S , 3 S )π + π − and χ b (1 P , 2 P )π + π − ; they observe peaks in ϒπ ± and χ b π ± consistent with J P =1 + . They interpret the peaks as molecular states Z b (10608) and Z b (10653). Their masses are just above and thresholds at 10604.6 and 10650.2 MeV. An explanation in terms of cusps at these thresholds is presented here. The product of the rising phase space for and with the cusps creates peaks a few MeV higher in and , and these peaks can de-excite to π + π − ϒ(1 S , 2 S , 3 S ) and π + π − χ b (1 P , 2 P ).